Piston for internal-combustion engines



July 28, 1925. E. DAIBER PISTON FOR INTERNAL COMBUSTION ENGINES F ledigo'v. 9; 1921 Patented July 28, 1925.

1,547,737 PATENT- OFFICE.

ERNST DAIBER, F KIEL, GERMANY, ASSIGNOB TO FRIED. KRUP]? AKTIEHGESELL- SOHAF'I GERHANIAWEBET, OT KIEL-GAABTEN, GERMANY.

PISTON FOR TN TERHAL-COIBUSTION GINES.

Application filed llo veniber 9,1921, mm a... 514,058.

To all whom it may concern:

Be it known that L'Enus'r DAIBER, residing at Kiel, Germany, a citizen of the German Republic, have invented a certain new and'useful Improvement in Pistons for Internal-Combustion Engines, of which the following is a Specification.

This invention-relates to air-cooled pistons for internal combustion engines and has for its object to take away in a particularly effective manner, the heat accumulated in the front wall of the piston and in the upper portion of the piston body.

This ob ect is chiefly attained by that the piston body is divided up, perpendicularly to its longitudinal axis, in two portions, and that the front wall of the piston and the upper ortion of the pistonbody connected to said front wall,'are supported by an inner piston body. This inner body which is preferably of conical shape and the lower wall portion of which terminates in the lower portion of the piston body, serves to transmit the working pressure exerted by the piston.

Several embodiments of the invention are illustrated in the drawings showing the respective pistons in longitudinal section.

,Fig. 1 is a longitudinal sectional view of one embodiment of the invention, and Fi 2, 3, 4 and 5 are fragmentary, longitu i'nal sectional views, respectively, of modified forms of the inventlon.

Referring first to Fig. 1, the body A of the piston is divided up, perpendicularly to its longitudinal axis, so as'to form an upper and a lower portion. The u per portion a is directly annexed to the wall a of the piston and is su ported, together with said front wall, hy 'a'coneshaped inner body a whose wall terminates at its lower edge in the wall of the lower portion a of the piston body. The circular gap existing between the portions a anda of the piston body is closed by a ring B which may serve, if desired also for lodging piston rings. 1

The inner istonbody a'gservesto transmit the wor ing1 pressure exerted by the piston, but its 0 ief destination is to lead away the heat accumulated in the front wall a to cooler portions of the iston aid to the air, thus producing a 000 ing effect.

The heat passes" from 'the front wall a? to I the inner body a and from the latter, it

easily flows away in a downward direction,

since the inner body is enlarged downwardly, thus offering to the heat to be led away a more and more increasing area, and

since the lower edge of the inner body goes over into the lower portion a of the piston 'body, this portion being relatively cool.

Further, the inner body a 'has a cooling action uponthe front wall a by that it takes up the heat radiating from the latter and transmits it onto the cooler lower por tion of the iston.

The descrlbed method of dividing u the piston body enables the front wall an the adjoining 11' per portion of the piston to expand as eely as possible when heated.

Another portion of the heat accumulated .in the front Wall a is transmitted to the the gap, if desired special yielding con-- necting members 0 of any well heat-conducting material, may be provided, as illus-.

trated in Fig. 2.

As further shown in this figure, connect- 7 ing members D of the described nature may likewise be provided between the front wall and cooler portions of the piston.

, Fig. 3 shows a piston of essentially s1mi-= lar construction but having a mushroomshaped fitting member E adapted to protect the front wall of the piston and known per se.'

The modifications illustrated in Figs. 4' and '5 differ from those described in" the foregoing lines merely in that the front wall and the up r portion of the piston body connected t ereto, are not cast 1n one piece with the lower piston portion, but arede-' tachably connected thereto. This construction enables to easily replace the front wall portion of the piston when damaged. A 190' mushroom-shaped protecting member may,

of course, also be applied to these modified pistons.

The essential feature of the invention consists in, that the central portion of the front wall of the piston is connected to cooler por tionsof the latter, andthat'the front wall is able to expand as unhindered as possible walls,

ton body.

owing to its being separated from the pis- By mea'ns'of thesetwo features, the front wall is not only cooled in a very efi'ective manner but also the stresses occurring in the front wall due to differences in temperature, are diminished in the highest possible degree.

Claims: I

1. A piston for internal combustion engines comprising atop wall and side walls, said side Walls being divided by a circumferential gap forming upper andlower side imperforate supporting walls for the top Wall extending convergently upward from said lower side walls and meeting said top wall at its center and additional heat conducting means associated wit-h said piston for conducting the heat from said top wall.

gines comprising a piston body and a front wall, said body being divided up, perpendicularly to its longitudinal axis, in two portions so as to form avgap between them, said front wall being connected to the ad jacent portion of said body, a heat-transmitting ring fitted in said gap, and a conewall's, imperforate jacent portion of said A piston for internal combustion en-v sai shaped inner body connecting said front wall to the other portion of said body.

3. A piston for internal combustion en'- gines comprising'a top wall and side walls, said side Walls being divided by a circumferential gap forming upper and lower side top wall extendin convergently upward from said side wal s and meeting said top wall at, its center, and disengageable connecting means between said top Wall and said side walls.

4. A pistonfor internal combustion engines comprising a piston bodyand a front wallpsaid body being divided up, perpendicularly to its longitudinal axis, in two portions so as to form a gap between them, said front wall being connected to the adbody, aheat-transmitting ring fitted in said gap, and a conesha ed inner body detachab y connecting b (xii front wall to the other portion of said 0 y.

The 'foregoingspecification si I Germany, this 11th day. of Octo er, 1921.

ERNST DAIBER.

ed at Kiel,

supporting walls for the 

